The invention relates to a composite material lay-up head for applying elongate fiber reinforcement material to an application surface. In particular, although not exclusively, the invention relates to a lay-up head having a guide eyelet through which elongate fiber reinforcement material is arranged to pass.
Fiber composite components are frequently used for applications requiring a combination of light weight and strength, for example in sports equipment and in aerospace components. Most fiber composite manufacturing processes require successive layers of fiber reinforcement material to be applied to a tool, article or a mould in a lay-up process to form a pre-form. A matrix material is typically pre-applied to the fiber reinforcement material (pre-impregnated, or “pre-preg”) before lay-up of the component. Recent manufacturing developments have allowed the lay-up process to be performed automatically.
Three types of automatic composite manufacturing processes are Automatic Tape Laying (ATL), Automatic Fiber Placement (AFP) and automatic filament winding. ATL relates to the application of a tape comprising fiber reinforcement material to a tool. The tape typically comprises unidirectional fibers which are pre-impregnated with matrix material (e.g. epoxy resin). Successive tape layers are typically applied at different orientations from one another to form a ply structure.
In AFP, the fiber reinforcement material is applied to a tool in the form of a “tow”, comprising a plurality of individual fibers, or multiple “tows”. Alternatively, a “tow” may be a narrow width of tape slit from a wider tape. AFP is typically more suitable for complex parts having a higher degree of curvature or non-uniform curvature. The fibers are typically pre-impregnated with matrix material or drawn through a bath of matrix material. A course or series of “tows” is typically applied to the tool by an applicator roller.
Automatic filament winding differs from AFP in that the tool is typically a rotating mandrel and the lay-up equipment typically traverses the mandrel to apply a tow of fibers in tension over the mandrel surface. The angle at which the tow is laid over the mandrel can be adjusted between successive passes of the mandrel such that successive layers lie at different orientations from one another to form a ply structure and to influence the properties of the component (e.g. improved compressive or tensile strength of the manufactured component).
In all of the processes a lay-up head is typically used to dispense and apply the fiber reinforcement material to the application surface. The fiber reinforcement material is typically fed or dispensed from a dispenser, known as a creel cabinet, which retains one or more reels of fiber reinforcement material. The fiber reinforcement material is typically guided to the lay-up head using one or more guide rollers, and enters the lay-up head through a guide opening. The lay-up head may comprise a feeding mechanism for feeding the fiber reinforcement material, and a cutting mechanism for severing lengths of material.
During lay-up, the lay-up head may move and rotate relative to the creel cabinet. It is important that the lay-up equipment can permit this relative movement without the fiber reinforcement material breaking. If the fiber reinforcement material breaks during lay-up, then the lay-up process must be stopped and the equipment reset. This downtime reduces the efficiency of the lay-up process.